Method of mixing or masticating heavy plastic material



July 3, 1923. I 1,460,938

V D. R. BOWEN ET AL METHOD OF MIXING OR MASTICATING HEAVY PLASTIC MATERIAL I 1 Original Filed sm. 14 1917 5 Sheets-Sheet #1 7 Mil 1... 26 I I! a, 4

. 3 Alli-I 45 I 42 I I A fiLI/e/IZZZIU: 1: m WWWW July 3,1923. 1,460,938

D. R, BOWEN ET AL I METHOD OF MIXING OHMAS'I TCATING HEAVY PLASTIC MATERIAL i l Fi led seat. 14, 1917 5 Sheets$heet 2 D. R. BOWENET AL Y METHOD OF MIXING OBMASTICATING HEAVY PLASTIC MATERIAL JulyB, 1923.

D. R. BOWEN ET AL METHOD OF MIXING OH MASTICATINGHEIAVY PLAsTIc' MATERIAL Original Filed sent. 14

1917 5 Sheets-Sheet 4 July 3, 1923. 1,460,938

7 D. R. BOWEN ET AL METHOD OF MIXING O'R MASTICATING HEAVY PLASTIC MATERIAL o igi Filed Sept. 14', 1917 5 Sheets-Sheet 5 2 x Z 255 x Wag 5 7 Patented July 3. 1923.

n rrs stares 15mm R. BOWENAN'D CARI/r. soHNUoK, or ANSONIA, CONNECTICUT, AssIGNORS' To] FARREL FOUNDRY AND MACHINE ooMPr'tNY.

PORATION or CONNECTICUT.

or .eNsoNrA, CGNNECTiCUT, A COR- METHOD or me e oniaAs ioAtrie HEAVY PLASTIC MATERIAL.

Original application filed september 14, 1917, Serial No. 191,413. Divided and. this application filed March 20, 1913. Serial No. 223,537. nenewea'rr'arch 12, 1923.

To all whom it may concern:

Be it known that we, Davin R. BOWEN and CARI; F. SCHNUCK, both citizens of the United States, and both residingin Jinsonia, county of New Haven, State of Connecticut, have invented certain new and useful Improvements in Methods of Mixing or Masticatin Heavy Plastic Material, of which the Iollowing isa full, clear, and exact description.

This application is a division of our applioation Serial No.,191,-l13, relating to a machine for treating rubber and similar material.

The present invention has particular ref ere'nce to an improved method of mixing or masticatin r rubber which is to be used for various industrial purposes. Our improved method is particularly adapted'to the mixing of rubber in the form: of fairly large chunks, with filling or coloring: material such as lampfiblack or the like in apowdered state. v c

One of the primary objects of the invention is to provide an improved method for reducing: to a smooth, uniform, plastic mass a mixture of the character described.

Another object of our invention is to provide a. method of mixing rubber, in which the mixing action is produced by extrusion of the mass under treatment. This has been found very efficacious in producing a homogeneous mixture in a very short space of time. I

Still another object of our invention is to provide a method of masticating rubber, in which the extrusion action can be carried out very conveniently. and wherein the mass can be worked very thoroughly by a mashing or smearing action as well as by extrusion.

To these and other ends, the invention consists in the novel steps and combinations of steps to be hereinafter described and claimed. I v

.Reference is to be had to the accompany ins drawings, wherein,

l is an end elevation of a rubber mixer for carryingout our improved method:

Fig. 2 is a vertical, longitudinal section with the mixing chamber closed and the pressure plunger in the raised position:

Fig. 2 is' a horizontal section through the body portion of the 2 2 of i; I v.

1 1g. 3 1s an end elevation of a port1ori of the machine with onset the end frames omitted; 4 i

Fig. 4 is section on line i -2t of Fig. 2;.

Fig. 5' is a transverse. vertical section of the machine, showing-the mixing chamber opened for the discharge: of theinixed material, and the pressure plun'gerin its lowere most position;

'Fig". tor;

Fig. rotor; I I

Fin. n is an end elevation of therotor, partly in transverse section, through one of the blades; and V i i l i s. 9, 10 and 11 are diagrammatic plan vic of the rotor and mixing chamber; showing different stages in the opea'rtion'of the blades. I

In carrying; out our improved methorhwe prefer to employ a machine of the kind shown in the drawings but 'it will be obvious that the construction of the machine may be considerably varied without departinoj from thesc'ope of the present invention. The particular machine selected for illus tration is characterized by a generally cylindrical mixing chamber which is adapted to be supported above the floor level and in which. there is journalled a single; approx-' imately central mixlnqel'ement' or rotor adapted to b'ci diiven'b v power applied to the rotor shaft. This machine is" intended tobe' charged at the top and discharged at the beam, for which purpose the mixing" charm her is provided at its upper portion witha 6 is a detail side elevation of the rois detail end elevation of the machine, takenv on line or chute into which the material to be treated is charged said stack or chute be'infaprovided interiorly with a fluid pres sure operated lunge or ranifor for ing the I'naterial down'iiito the chamber against the rotor. while the lower part of the mixing; chamber is movably morin'tedto The end frames and the body portion of the cylinder may be conveniently interconnected by bolts 24. A. rotary mixing element or rotor is provided within the mixing rotor shaft 25* may be conveniently formed in adjustable stuffing box glands 26 located in the respective end frames at the ends of the cylinder, and preferably made of brass or other suitable bearing metal. The stufiing boxes with which the glands 26 are associated are adapted to prevent escape from the ends of the cylinder around the shaft of the material being treated, and they comprise one or more rings 27 of suitable packing or the like, fitted in a recess around the shaft and compressed by the corresponding gland which is adjustable by means of bolts 1 28. In the example shown the shaft 25* is adapted to be rotated in the direction of the arrow 2) by power applied to a pulley (not shown) on one end of the shaft.

At the'upper portion of the mixing chamber, the same is provided with an upright stack, or chute 29, which may be conveniently cast integral with the main body portion of the cylinder. Near the upper end of the stack or chute is a charging opening 30 through which material to be treated is introduced, and operating in the stack is a charging device in the form of a pressure plunger 31, movable up and down by a fluid pressure cylinder and piston device 32, supported on top of the stack. P The plunger 31 has a rod 33 extending, upward into the cylinder 34, and on the rod 33 is a piston 35. In the particular example shown, the plunger 31 is hydraulically operated, for which purpose a water connection 36 is provided at the top of the cylinder 34 above piston 35, while a second water. connection 37 is provided at the lower part of the cylinder. The connections 36, 37 are controlled by valves in an obvious manner, so as to produce theupward and downward movement of the pressure plunger 31, in a manner which is well understood. hen the material to be mg is presented for the discharge of the material, usually in a downward direction. For this purpose themachine shown in the drawing has the entire lower portion 38 of chamber 20 arranged so thatit can be moved downward to open the lower part or" the machine, and the movable wall portion38 of the chamber is preferably. hinged at one side of the chamber, as shown at 39, so that it can swing downward into the discharging position shown in Fig. 5. In the particular example illustrated, the lower movable section 38 comprises approximately half of the main mixing chamber wall. said mixing chamber being divided longitudinally and diametrically, but, of course, this is not essential in all cases. Furthermore, the method of hinging the movable section 38 and the means for looking it in place may vary considerably as called for by different conditions. In the case under discussion, tl e hinge connection 39-consists of a pintle which passes through alternately arranged knuckles on the main body of the chamber wall and on the movable part 38. In Fig. 2, it will be observed that the knuckles of the main or body portion of the chamber wall are indicated at 20, while the knuckles of part 38 are designated 38*. At the opposite side of the mixing chamber, swinging locking bolts 40 having nuts 41 are pivoted to lugs 42 on the body portion of the chamber, so as to hang down therefrom, and the nuts 41. are adapted to. engage'the under surface of a lateral slotted lug or flange 43 at the free edge of the hinged section 38 to clamp the two sections of the casing or chamber-together. Ehe lug 43=is provided with slots 4.4 into which the bolts" 40 are adapted to swing, as shown more particularly in Fig. 2 By screwing upthenuts 41, the machined meeting edges of the casing or chambersections maybe forced int-otight contact to prevent effectively the escape of any of the treated material at the joint between the sections. s p

The rotor 25 shownin the drawing is provided with a blade or blades which not only havean aflective wedging or mashinn; action. to wedge or mash the material against the wall of the chamber, but also have a sort extruding action in torcing the material (usually in a generally longitudinal direction) through one or more constricted portions of the chamber which is available for holding. the material to be treated. Preferably the available inder, and then in the opposite direction,

so that the mass'of rubber is worked altercontinuous.

nee ess nately from one end of the mixing chamber to the other; although 'lnsome aspects of the invention all these features are not esinder another blade located at that end then takes up the work andejects the mate-- rial from said end of the cylinder back into that end inivhich it was initially located, and so on 'the working; action of the blades on the material being substantially preierence also, the constriction of the-material-holding space of the m' chamber will be provided by a tra e gs rib or similar constriction formed on or associated with the generally cylindrical wall of the chamber.

In the example shown, the rotor is provided within the mi enlargement or hub 25% on which two blades 25* are provided, one 0t said blades being located in one end of and the other inthe opposite end blades5moreo er, are located appr diametrically with respect to the shaft axis, as shown; for example in rig. 7. ln this particular example, each blade eiitends an proximately throughout one hall of the 1n 4 ing chamber length, and both blades co the mixing: chaniibei' operate with a transverse rib or ridge 4-5 on the chamber wall located intermediate of the ends of the chamber. i i-S illu trated. this rib is continuous except for the interruption at the upper part where the stack 99 communicates with the upper part ot the chamber and the blades25" are so shaped to cooperate with the. rib in producing an extrusion of the rubber from one end portion of the chamber to the'other and back again. The blades 2-5" provided wit tacetedworking faces 915; which effectively grip the material and force it against the cylindrical wall. of the mixing chamber as the rotor rotates, while at the same time the material is forced lengthwise lot the chamber by incliningthe blades relatively to he shaft axis. Referring particularly to 2 it will he'observed that when the rotor is rotated in the direction of the arrow. the

faceted worxin'e; urfaces 2510? the blades will have a wed I and mashing action on the inat'erial"which is forced thereby into contact w I chamber; while at the same time the inclination oi the blades relatiyely to the axis of the rotor ca'usesthe upper blade; shown in 9., to worlrthe material towar'd the left while the'lower blade forces the; material to the ht. This movement of the material lfillgthNlSG of the chamber necessitates itspassage through the constricted chamber with an matelyj the cylindrical wall of the portion vof the chamberpro ided or created by the transverse rib 45, and the blades are cut away at their inner portions so as to space in the other'end of the'ch'amber. Thus it will beunderstood that each bl adenot only smears or meshes the rubber against. the cylindrical part of the chamber W311i but it also to'rces' smears or mashes it against the rib 45 in a chrection transverse to the rib, saidr'ib beingpreferablypro-,

vided with flat inclined sides over which the material travels lnwardly and long;-

tudinally of the 'cylinder although the cross-section of the rib may be considerably varied in somecases.

rubber in the torm of large chunks wi'th fillingv or colorlng material in powdered In each end of they cylinder; "the material is subjected 'to a;- mazriinum amount of working or mastication so that for enampla a mixture of erm can bereduced ins short time to a sirooth -ilastic mass in wh ch the distrlbu iioifot the various inefredients isunitorm throughout. After being worked in one end 0t the cylinder, the material ish forced into the other end, Where y it is .worked as in; and it is then forcedback into the f st end, this operation beinfg'repeated in-i definitel until the desired results have been obtained.

During this operatibn, the material is heldv against the rotor by the pressure plunger or' follower'31 and the temperature of the mate rial can'be controlled to a certain extent by means otwater, steam or other fluid introduced into the mixing chamber wall and the interior of. the rotor, which may be madehoL low for'this purpose. lnthe present case, we have shown a hollow rotor but we have not considered it necessary to illustrate a jacketed chamber as this in itself is a wellknown feature. v

The mixingor masticating operation having been completed the 'machine is dis-v charged by opening the" lower para of the mixing chamber, as shown in 5., T he 'rov closed, and the pressure plungeris raised material, i v v r p particular form shown the rotor hub is enlarged atthe middle porti'ombei'ng In the body portion beingespecially reflective in this'refzarc. j V Zhen all of the treated material has been stripped off and discharged. the n iXing" chamber is preliminary to operation onanotlier batch formed, in effect of two cone trustumswith their bases together. The blades 25 are bevelled oit at their inner portions toconform to'the rib as shown at 25, and their inner ends are located closely adjacent the center of the hub and the center of the rib, so as to press the material'forcibly through the narrow, are shaped extrusion opening which is provided at that point, in a direction which is generally lengthwise of the chamber. The

formation of any pockets in which inert material can collect.

The path of movement taken by the mate rial during the mixing operation will be clear from an inspection of Figs. 9 to 11. It

will be apparent that while one blade is forcing and wedging the material against one side face of the rib, and thereby extruding it through the constricted portion of the chamher, the other blade is doing the same thing at the other side face of the rib or other constriction, although, in the example shown, this occurs-at a diametrically opposite point. It will be observedthat the space through which the material is obliged to pass in moving from one end portion of the chamber into the other in a direction generally lengthwise of the rotor axis, is very small in comparison to the cubical contents of the whole chamber.

Th e-niass or" material in the chamber has a volume considerably greater than the extrusion space so that the material is necessarily forced through said space under heavy pressure to produce a squeezing action. In the extrusion space, the material is densely packed and it is heavily squeezed to produce a continuous rearrangement otthe molecules. In'this manner, when rubber and powder are being mixed, the rubber mass is continually opened up so as to present new raw surfaces to absorb the powder, and the rubber and powder are mixed together very intimately and homogeneously.

Various changes may be made in the spe cific procedure herein described, without departing from the broad principles of our invention as defined in'thecl'aims.

, It will be obvious that we do not limit our selves in all aspects of the invention to a method n which a smearingaction is combined withan extruding action, for in some cases, the smearing action can be altogether dispensed with. In the preferred practice, the extrusion is produced by forcing substaiitially the whole mass back and forth through an opening of ve y small cross-sectional area in comparison to the total volume of the mass of material being treated; but we 'do notlimit ourselves, in all. aspects of the invention, to this feature, nor to the treatment ot'the par-. ticular' iaterials mentioned herein.

We do not claim herein the method of mixing rubber or similar material which comprises working the same back and forth against a substantially circumferentially continuous cylindrical mixing surface] or other features claimed rial No. 458,222.

What we claim is: i I g l. Themethod of compounding rubber, which comprises placing the material "to i be compounded in a suitable chamber, and ex:

truding the mass through a constrictedopen ing a multiplicityof times before removing the same from the chambe 2. The method of masticatiiig rubber'o'r similar material, which comprises extruding the material through a constrictedopening under heavy pressure in opposite directions. i

in our application, See.

3. The method of mixing rubber With coloring matter or the like, which comprisesextruding the material through'a single constricted opening under heavy pressure alteriiatelyin opposite directions. v

4L-The method of compounding rubber, which comprises placing a mass of material in a suitable chamber, and extruding the mass through a constricted opening, preliminary to its discharge from the chamber.

5. The method of mixingrubber with filling or coloring material, which comprises placing the mixture in a suitable chamber,

mashing or smearing the same against the. chamber wall, forcing it one or more times I through a constricted opening, and then dis charging the mixture from'the chamber.

67 The method of mixing rubber chunks with filling or coloring material in powdered form, which comprises extruding the preliminary mixture through constricted opening in opposite directions amultiplicity of times.

7. The method of masticating rubber or similar material, which comprises placing the batch within a suitable chamber, then extruding it under heavypressure through an appropriate extrusion space within the chamber, until the mass has the desired plasticity and homogeneity-and then dis charging. the mass from v the chamber.

8; The method of mixing rubber chunks with powdered filling or coloring material, which comprises extruding the mass of rubher and powdered material through a constricted opening alternately in opposite directions. i f

9. The method of working rubber and similar material which comprises placing the mass in a suitable chamber, smearing or mashing a portion of the material of the mass against the chamber wall, simultaneously extruding another portion of the ma.- terial through a constricted opening, and then discharging the mass from the chamber.

10. The method or working rubber, which and subjecting the mass to a mixingextru sion action for thoroughly masticating-the mass within the chamber.

13. The method of mixing heavy plastic material having two or more ingredients, which comprises the continued and repeated extrusion of the mass under heavy pressure through a singleconstrioted opening alter-' nately in opposite directions.

14. The method of mixing heavy plastic material having two or more ingredients, which comprises the continued and repeated extrusion of the mass through a constricted opening alternately in opposite directions,

combined with the simultaneous mashing, or

smearing of a portion of the mass against. a suitable surface.

15. The method of masticating rubber and similar material, which comprises introducing the material 1nto a sultable chamber and from 'oneend of the chamber to subjecting the mass in' the chamber to a repeated mixing extrusion action within the chamber. I, i

16. The method of mixing powder with rubber or a similar substance, which comprises squeezing substantially1 the whole mass of rubber and powder through an open ing of such constricted cross-section as to produce an extrusion and mixing with a thorough rearrangement of the molecules.

17. The method of mixing powder with rubber or a similar substance, which comprises squeezing substantially the whole mass of rubber and powder through an opening of such constricted cross-section as to produce an extrusion and mixing with a thorough rearrangement of the molecules, and repeating the extrusion ofthe mass a multiplicity of times.

18. The method of masticating heavy plastic'material, which comprises forcing. the mass through an opening; of. such restricted cross-sectional area relatively to the volume of the mass as to produce an extrusion action, with a consequentrearrangement of the mole cules, an'd then forcing the mass 1 through such opening in the opposite direction toflrepeat the extrusion thereof.

' .19. The method of masticating or working heavy plastic material, which comprises placing the same 'in' asuit-able chamber, and

squeezing'it through a constricted opening and back again. v

In" witness whereof, -we have hereunto set our hands on the 18th day OfMZLICll, 1918. 1

DAVID R. BOWEN.

CARL r. sonNUox.

the other 

